1. Technical Field of the Invention
The present invention relates to a vibration motor which is used in a portable electronic equipment such as a portable telephone, a pocket bell or the like, and which silently informs a user of incoming etc. by vibration, and relates to a portable electronic equipment having the vibration motor.
2. Description of the Related Art
JP-A-10-248203 discloses one of conventional vibration motors used as silent information sources in miniature radio communication equipment, in which a cored-type brushless vibration motor is disclosed.
FIG. 6 is a sectional view of a main portion of the cored-type brushless vibration motor.
In FIG. 6, a bearing holder portion 102 is provided at the center of a bracket 101 forming the bottom of the vibration motor. This bearing holder portion 102 has a catch portion 103 and an erected portion 104 formed by cutting and erecting a part of the bracket 101.
A sintered oilless bearing 105 is attached to the inside of this bearing holder portion 102 through a cover plate 106, and a stator core 109 having an armature coil 108 wound on a plurality of salient poles 107 is attached to the outside.
A rotor 110 has a magnet holder 111 and a cylindrical magnet 113 fixed to the magnet holder 111 and having a plurality of field poles disposed in a blade portion 112 of the stator core 109 through a radial gap. Further, the rotating body 110 is fitted by pressing a shaft 115 into a burringhole 114 disposed at the rotation center of the magnet 113. In addition, one end of the shaft 115 is rotatably supported by the sintered oilless bearing 105, and the other end is rotatably supported through a similar sintered oilless bearing by a case 116 having another function as a cover.
In addition, a power supply method is to connect a terminal of the coil to one side of a flexible printed board so as to drive the motor.
However, in the above-mentioned conventional art, a usual vibration motor is extracted by an automatic sucking machine, automatically arranged on a board and subjected to assembling in a normal automatic assembling/wiring process in the case where the vibration motor is supplied by a parts maker in the packaged form of a pallet, a reel or the like. In that case, first, the vibration motor cannot be extracted by the automatic sucking machine if the vibration motor has a shape similar to that as mentioned above. That is, the automatic sucking machine sucks the ceiling of a part pneumatically. However, the aforementioned vibration motor is not even in the ceiling of the vibration motor because a sintered oilless bearing for rotatably supporting a shaft lies at the center of a cover. Therefore, even if the ceiling is sucked pneumatically by the automatic sucking machine, the air leaks from a gap between the shaft and the bearing so that sucking of the ceiling cannot be performed
Further, since the vibration motor in the conventional art is not designed to suit a reflow soldering, special parts are required for assembling the vibration motor into a miniature radio communication equipment and holding the vibration motor therein, and the work for making the above operation demands expert employees, so that the number of labor-hour and the cost are increased. It is therefore necessary to make the vibration motor at least suitable for the reflow soldering so that the vibration motor can be applied to an automatic assembling process for mass production.
In the reflow soldering method, after parts to be mounted are arranged on a printed board, the parts and the board are passed through a ref low furnace so as to be connected with each other by solder. This solder is obtained in a way such that creamy solder is passed through an atmosphere at a high temperature to be fused and then the fused solder is solidified after being cooled. Here, it is necessary to pay attention to the case where solder balls scattering in the reflow furnace adhere to a coil or a magnet in the middle of the reflow soldering. In that case, it is necessary to give enough consideration to such a trouble that such an adhering solder ball blocks starting when the vibration motor starts, or such a solder ball rubs on the coil, the magnet or the like so as to generate irregular noise, etc.
In addition, even if the vibration motor is mounted on the printed board, it is necessary to perform accurate or proper positioning of the vibration motor. It is therefore necessary to take a dimensional measurement of the mounted position of the vibration motor. There are a large number of problems like the above matters when the reflow soldering is performed.
That is, in order to perform the reflow soldering perfectly so as to automate a wiring/assembling process, there has been a problem that automation must be fulfilled in all the steps of the following items 1 to 4 while the quality have to be also guaranteed.
1. To extract supplied parts by means of an automatic sucking machine or the like.
2. To arrange the extracted parts onto a printed board automatically.
3. To take measures against solder balls in a reflow furnace.
4. To inspect the positions of the parts after the parts are mounted.
An object of the present invention is to provide a vibration motor holding apparatus in which a configuration of a vibration generating means is realized with guaranteed quality by all the steps of extracting supplied parts, automatically arranging the parts onto a printed board, taking measures against solder balls in a reflow furnace, and identifying/inspecting the positions of the parts after the parts are mounted, in order to perform reflow soldering upon the vibration generating means together with other electronic parts on the same printed board in a lump without using any special parts such as elastic or inelastic holding members or the like.
In order to achieve the above object, according to a first aspect of the present invention, there is provided a vibration motor holding apparatus comprising: a rotating body having a rotary member provided on an external surface of a base, and a cover for covering the rotary member; and a board on which the rotating body is mounted; wherein a position identifying mark is provided on the board in order to mount the rotating body in a predetermined position on the board, the position identifying mark being exposed or bared in the outside of an outline of the rotating body when the rotating body is mounted in the predetermined position on the board.
With this configuration, in the case where a motor such as a cored-type brushless motor, a coreless brushless motor, a brush-type motor, or the like, is used as a vibration motor to function as a rotating body, when the rotating body of any type of such motors is mounted on a printed board, automatic arrangement of the rotating body on the printed board can be made easily by automatically sucking the ceiling of the cover of the rotating body. It can be confirmed from above that the identification mark provided outside the rotating body attachment position on the board is hidden by the rotating body if the position of the rotating body mounted on the board is abnormal, while the mark is exposed or bared in the outside of the rotating body when the position is normal. It is therefore possible to easily identify, judge and inspect whether terminals on the base on the rotating body side are surely connected to corresponding main-body lands on the board or not, whether the terminals are short-circuited with other lands or not, whether the rotating body does not abut against other parts or not, and so on.
According to a second aspect of the present invention, there is provided a vibration motor holding apparatus comprising: a vibration motor having a base in which terminals are formed on a back surface or a side surface of the base, a stator in which a coil is wound around a stator core, a magnet disposed in opposition to the stator, and a cover provided to cover the stator and the magnet, the stator and the magnet being disposed on a front surface side of the base so that one of the stator and the magnet is not rotatable relatively to the base while the other is rotatable; and a board on which the vibration motor is mounted; wherein a position identifying mark exposed or bared in the outside of an outline of the vibration motor mounted in a predetermined position on the board is provided on the board.
With this configuration, the vibration motor is constituted by a brushless motor constituted by a stator in which a coil is wound on a stator core, and a rotor magnet. When the vibration motor is mounted on a printed board, the cover ceiling of the vibration motor is sucked automatically so that it becomes easy to arrange the vibration motor on the board automatically. It can be confirmed from above that the identification mark provided outside the vibration motor attachment position on the board is hidden by the vibration motor if the position of the vibration motor mounted on the board is abnormal, while the mark is exposed or bared in the outside of the vibration motor if the position is normal. It is therefore possible to easily identify, judge and inspect whether terminals on the base on the vibration motor side are surely connected to corresponding main-body lands on the board or not, whether the terminals are short-circuited with other lands or not, and so on.
According to a third aspect of the present invention, there is provided a vibration motor holding apparatus comprising: a rotating body having a base, a rotary member provided on a front surface side of the base, and a cover having an electromagnetically shielding property and provided to cover the rotary member; a board on which the rotating body is mounted; and a shield member provided to cover at least a part of the board; wherein the rotating body is disposed inside the shield member
With this configuration, noise generated from the rotating body which may be constituted by various motors can be prevented from leaking outside the rotating body. In addition, it may not be necessary to provide a shield member for electromagnetically shielding the rotating body from other parts mounted on the board. It is therefore possible to ensure a mounting area on the printed board as large as possible, so that it is possible to improve the mounting efficiency.
According to a fourth aspect of the present invention, there is provided a vibration motor holding apparatus comprising: a vibration motor having a base in which terminals are formed on a back surface or a side surface of the base, a stator in which a coil is wound around a stator core, a magnet disposed in opposition to the stator, and a cover provided to cover the stator and the magnet, the stator and the magnet being disposed on a front surface side of the base so that one of the stator and the magnet is not rotatable relatively to the base while the other is rotatable; a board on which the vibration motor is mounted; and a shield member provided to cover parts mounted on the board; wherein the vibration motor is disposed inside the shield member.
With this configuration, noise generated from the vibration motor constituted by a brushless motor is prevented from leaking outside the vibration motor. In addition, it may not be necessary to provide a shield member for electromagnetically shielding the vibration motor from other parts mounted on the board. It is therefore possible to ensure a mounting area on the printed board as large as possible, so that it is possible to improve the mounting efficiency.
According to a fifth aspect of the present invention, in the above vibration motor holding apparatus, an air hole is provided in the cover so as to connect spaces inside and outside the cover to each other.
When electronic parts, a motor, and so on constituting a receiving circuit portion or a radio circuit portion pass through a reflow furnace together with the main-body printed board, these electronic parts, motor, etc. pass through an atmosphere at 150xc2x0 C. to 250xc2x0 C. for a predetermined period. At this time, if the inside of the cover had a closed structure as in the background art, force was generated against the internal surface of the cover due to thermal expansion of air in the inside of the cover so that the cover was separated from the motor printed board. However, with the above-mentioned configuration, very small air holes connecting the outside and the inside of the cover are provided so that the air inside the cover can be prevented from expanding. It is therefore possible to avoid an unexpected situation such as the separation of the cover or the like.
According to a sixth aspect of the present invention, in the above vibration motor holding apparatus, a portion of the cover is made to contact against the surface of the base so as to perform positioning of the cover in the height direction.
With this configuration, the distance between the ceiling of the cover and the back surface of the base, that is, the height of parts can be formed with precision if the parts are formed so that the distances between the abutment surfaces of the parts against the base and the ceilings of the parts do not scatter, and if the thickness of the base is controlled. It is possible to easily distinguish the case where the vibration motor is mounted abnormally with foreign matters etc. interposed between the base and the board, from the case where the vibration motor is mounted normally.
According to a seventh aspect of the present invention, in the above vibration motor holding apparatus, at least one of the mark, marking on the top surface of the cover, shapes of the base and the cover, and a fillet formed outside the base is used for positioning the vibration motor.
With this configuration, it is possible to accurately detect a displacement in the vibration motor mounting position in a two-dimensional direction (the planar direction of the board).
According to an eighth aspect of the present invention, in the above vibration motor holding apparatus, the cover is electrically connected to the board.
With this configuration, it is possible to ground the cover.
According to a ninth aspect of the present invention, in the above vibration motor holding apparatus, the mark is a grounding pattern.
With this configuration, if the mark for position identification is a grounding pattern, it may not be necessary to screen-print solder on the mark. It is therefore possible to make the mark function as an identification mark because the state of the surface of the mark does not change even after mounting.
According to a tenth aspect of the present invention, there is provided a portable electronic equipment provided with a vibration motor holding apparatus according to any one of the first to ninth aspects of the present invention.
With this configuration, in a portable electronic equipment, the vibration motor can be attached into a reduced space as a silent information means for informing a user of incoming or the like silently by vibration.